Published: Mar 27, 2014 7:46 PM EDT
Updated: Mar 28, 2014 12:32 PM EDT

COLLIER COUNTY, Fla.-Red flags on mailboxes - fraud detectives say it's an invitation for crooks to come and get your money. The Collier County Sheriff's Office tells WINK News, it's seeing a spike in the number of "check washing" cases.

"Pretty much anything legal as well as criminal it's all on the internet and the YouTube is no exception, it's just one avenue."

And WINK News is learning that avenue is giving crooks in Collier County another way to steal your money.

"Where their checks have been intercepted in the mail," said Lt. Chad Parker with the Collier County Sheriff's Office. Checks are being stolen, then cleaned with products found right in your home. Nail polish remover, rubbing alcohol, even bleach are helping bad guys cash in and the Internet is showing them how.

"Using that cleaning device you can get regular ink off the paper."

"And it comes out perfectly dry, you'd never even know that it went through a liquid solution," said fraud expert, Carrie Kerskie.

Pay attention because how you fill out your checks can make a big difference. Fraud detectives said you should use gel pens over standard ink pens.

"Those are really easy to wash."

The only thing thieves are not washing off is your signature. They erase the money amount, then write in whatever they want, and head to the bank. Identity theft expert Carrie Kerskie said an easy way around this whole thing, is to do online banking.

"Most people when they pay their bills, they put it out in their mail box, lift up the red flag and then they leave for the day. Well that's just a warning sign or an invitation to criminals to come and get it."

The Sheriff's Office recently created an identity theft task force. There are monthly meetings where you can learn how to protect yourself from all kinds of identity theft. The following meetings take place in April and May:

April 21 - North Naples Fire and Rescue Training Center, 1885 Veterans Park Drive, starting at 5pm.

May 1 - The Jewish Family and Community Center, 5025 Castello Drive, starting at 5pm.